Objective
A.BACKGROUND
A.1:Karst groundwater as a valuable resource
The existing European regulations (COM 96/59 final, 21 February 1996; Groundwater 80/68/EEC Council Directive) rank the protection of drinking water supplies (mainly groundwater) as a very high priority. Carbonate rocks, many of which are karstic, underlie 35% of Europe and often are the only economically acceptable source of water. Numerous important European cities, such as Innsbruck, Montpellier, Neufchtel, Paris, Rijeka, Rome, Thessaloniki and Vienna are largely dependent on karstic aquifers for their water supplies. This was stressed in the guidelines for karstic groundwater protection prepared by the previous COST Action 65 (1995). Karst groundwater thus is a vital resource for the future health and economic wellbeing of Europe. However, because of their special features, karstic aquifers are exceptionally vulnerable to contamination. This is because of their heterogeneity which results in huge variations in permeability and enables poorly filtered concentrated recharge to take place. Indeed, recharge can be swift and violent, allowing little time for the filtration of contaminants or the action of auto-purification processes.
The complex properties and behaviour of karstic aquifers requires additional multidisciplinary research as was pointed out very recently by the EC Task Force Environment Eau (EC, 1996).
A2:Vulnerability mapping
Due to their exceptional properties, karstic aquifers require special protection involving a multifactorial approach and the use of vulnerability mapping. Since the late 1960's, groundwater vulnerability (Vulnerability is an intrinsic property of a groundwater system. This is a general property that is used for characterizing, with the help of geological and hydrogeological information, the sensitivity of aquifer systems to either a point or diffuse anthropogeneous contaminations.
) mapping has played an increasingly important role in locating contaminant sites as well as bringing the importance of groundwater to the attention of decision-makers and planners. Vulnerability maps are rapidly becoming an essential part of groundwater protection schemes and a valuable tool in environmental management.
Vulnerability mapping, especially that of karstic systems requires field studies of several factors. According to the results of COST Action 65, these factors can be grouped in general categories such as "soil", "the type of recharge", "saturated and non-saturated zone" including the degree of development of the karst network and must be in accordance with a conceptual model of karstic aquifer describing the actual behaviour of the karst. Moreover vulnerability maps at the scale of a karstic catchment are still very rare.
These factors have been used to produce general or intrinsic vulnerability maps at three karst test sites in Switzerland. Some rather similar approaches are being tried out in other countries (Germany, Ireland); it will be necessary to integrate the experiments, the experience and the knowledge gained by the different countries. Intrinsic vulnerability mapping complies with existing groundwater regulation, since various degrees of vulnerability can be used to define protection zones with their corresponding restrictions in land-use.
Because specific contaminants (Contamination: all anthropogenic solutes introduced into the hydrologic environment are referred to as contaminants regardless of whether or not the concentrations reach levels that cause significant degradation of water quality. In contrary, the term pollution is reserved for situations where contaminant concentrations attain levels that are considered to be objectionable with the standard level defined in the law.
) are causing large-scale water quality problems, it will soon be necessary to provide specific vulnerability maps as tools in groundwater management. Dynamic and temporal parameters will need to be taken into account in the assessment of specific contaminant vulnerability. Such contaminants include nitrates, organic fertilizers and chlorinated solvents.
Both intrinsic and specific (The "general or intrinsic vulnerability" is defined only as a function of hydrogeological factors. In addition to intrinsic properties of an aquifer or a groundwater system, we can include potential human impacts on or risk to the system. In this case the term "specific" vulnerability is used.
) vulnerability maps are certain to become important tools and widely used in water quality management in the near future. In summary, vulnerability mapping in combination with potential risk maps, already available in a lot of countries, will be required in order to help protect and save present water supplies and those of the future.
At a continental scale, vulnerability mapping in the karstic environment provides a most useful tool to ensure the future of Europe's karstic groundwater resources, by affording vulnerability maps that will contribute to the improvement of the present quality of the karstic groundwater. Moreover, protecting the karstic groundwater resource avoids the high costs associated with sophisticated water treatment processes.
B.OBJECTIVES AND BENEFITS
First, based on the results of COST Action 65, the main goal of this Action is to propose an objective approach of - intrinsic and specific - vulnerability mapping in karstic environments taking into account potential risks.
Secondly, another important goal of this Action is to attempt to achieve some European level of consistency in the establishment of vulnerability and risk mapping, taking into account specific regional environmental variations as well as the different stages of economic development and scientific investigation of karst.
The anticipated outcome of this Action will provide very important tools for water management in the future and guarantee that karstic groundwater will remain a valuable resource. It will then be possible to develop appropriate land-use taking into account the vulnerability and the potential risk of contamination of water catchment areas. Thus the use of methodology providing very large protection zones with uneconomical land-use restrictions will be avoided. The proposed multicriteria method will allow both land-use restrictions for certain highly vulnerable areas and the development of economical activities in other parts of the water catchment basin with very low vulnerability.
The use of GIS tools will provide digitized vulnerability maps easy to update in which new data can regularly be incorporated.
Foreseeable difficulties:
-to bring together scientists of different fields in an interdisciplinary study: a special effort will be required to formulate clearly the problems to be solved and to understand one another,
-to be able to cope with the lack of data at some test sites where it would be worthwhile to use the vulnerability mapping approach: scientific investigations of karst, environmental protection and the different socio-economic environments will be taken into account in this Action. The lack of data will be compensated by a probabilistic approach, using fuzzy logic on the vulnerability maps.
C.SCIENTIFIC PROGRAMME
C1:Generalities
The scientific programme of this Action is divided into three parts:
-the first is related to the gathering of knowledge from the different partners of the Action,
-in the second part some approaches will be proposed for the vulnerability mapping of karstic aquifers and the specific problems will be identified. Two working groups will be created to develop a methodology for each of the two kinds of vulnerability mapping - intrinsic and specific. These will take into account the hydrogeological behaviour of karst, the problems related to the availability of data and the calibration and validation of the vulnerability assessment,
-in the third part, and simultaneously to the second part, each partner will use the methodology in at least one test site or more to develop an intrinsic vulnerability map. Additionally, in the same site or only in part of it, vulnerability mapping for a specific contaminant will be achieved. Test sites will be selected taking into account different karstic/hydrogeological settings (tabular, folded, deep, shallow, karstic fissured aquifers) and availability of data (water catchment boundaries, tracing tests, land-use, water quality analyses, hydrogeological characteristics) as well as various classes of contaminants.
C2:Intrinsic vulnerability mapping (Working group A)
Protecting karstic groundwater requires a multifactorial approach which takes into consideration the karstic hydrogeological characteristics and behaviour (high heterogeneity, high permeability in the conduits in contrast to low permeability in the surrounding blocks, dispersed and concentrated infiltration).
Working group A will define the major and secondary factors needed to prepare the intrinsic vulnerability maps. As these factors relate to the conceptual model of a karstic aquifer they could be defined as: geomorphological features (translation of the hydraulic behaviour of the epikarst), the soil and detrital overlayers (thickness and permeability), infiltration conditions (recharge), the karstic network development. Other factors, such as topography, runoff coefficient, thickness of the unsaturated zone used in some indexation methods (Vrba et al., 1994), will be included in the study. New factors including economic criteria and a weighting system representing their relative importance will be developed.
C3:Specific vulnerability mapping (Working group B)
In the future, the management of karstic groundwater will more and more have to face contamination problems. Working group B will focus both on the issue of specific vulnerability maps alone and also on specific vulnerability maps combined with maps of potential risk of contamination.
As the transport and the fate of contaminants are a function of their chemical, physical and biological properties, it is necessary to define new factors to be considered. Generally, the predominant contaminants in groundwater are heavy metals, organic chemicals, fertilizers, pesticides, bacteria and viruses. Various processes (geochemical with adsorption - desorption, solution - precipitation, oxidation-reduction, biochemical, physical with advection, dispersion and diffusion, retardation, filtration) affect contaminant transport and fate. These processes are dependent on the aquifer material and soil as well as on the biological and chemical conditions (pH, Eh, temperature).
Not only hydrogeologists but also scientists from other disciplines will participate in these Working groups. They will help to define specific factors (biological half-life, sorption coefficient, aqueous solubility, etc.) for each contaminant under study. The characteristics of the aquifer material (soil pH, saturated water content, cation exchange capacity, content of organic matter, hydraulic parameters, etc.) will also be included. For all these factors appropriate weighting systems will be developed.
The question of availability of data, the relativity of the vulnerability assessment and the calibration-validation of the vulnerability maps will be treated in both Working groups.
C4:Major points of the scientific programme
-Inventory of the factors responsible for vulnerability, such as, for instance, protective cover, infiltration conditions, epikarst, karstic network's development, etc.
-Definition and determination of the general sensitivity of the factors, and of a ranging and ranking system that is adequate for an intrinsic vulnerability mapping.
-Determining the relative importance of the factors concerning contaminants, on the basis of contaminant categories. These factors include both dynamic and temporal parameters. The potential attenuation capacity of the aquifer system will be determined. Persistant and mobile contaminants will also be differentiated. This will require the assistance of specialists from fields such as physics, pedo-geochemistry, chemistry, biology, agronomy.
-Establishing a methodology for the construction of intrinsic vulnerability maps and of specific vulnerability maps. These maps are prepared both by taking into account potential risks and by considering several specific factors.
-Using the GIS (Geographical Information System) tool as much as possible to obtain some synoptic vulnerability maps. This will require collaboration with Institutes specialized in GIS and its development (Geographic, Cartographic, Photogrammetry Departments). The GIS tool has already been used in vulnerability mapping by various Institutes involved in this proposed Action, and gives very promising results.
In the frame of this Action, PhD and Master projects are already planned in five of the institutes involved in the proposal. In fact, both in Switzerland and in Belgium work has already been initiated. Detailed programmes on vulnerability mapping are also planned or under way in countries such as Austria, Germany, Ireland, Poland and Slovakia.
D.ORGANIZATION AND TIMETABLE
This Action is subdivided into several phases, over a period of 5 years. The first phase of the Action will last one year. Its main objective will be to gather the knowledge of the participants on the intrinsic and specific overlay index methods used to assess the vulnerability of karstic fissured aquifers. Hydrogeologists and chemists and soil physicists will define several approaches of overlay index methods related to conceptual models of karstic aquifer, incorporating the specific problems of each hydrogeological setting, major contaminants, availability of data, etc. At the end of the first part, two working groups will be set up (Working group A and Working group B).
During the second part (18 months), the national delegates will work together in two groups. In each group, ad hoc specialists will be incorporated. Working group A is dedicated to intrinsic vulnerability. It will define the basic intrinsic factors necessary to assess vulnerability and an adequate weighting system (ranking and ranging, matrix system, etc.). Working group B will define the contaminant categories to study and also the related specific factors. As in Working group A, it will be necessary to determine an adequate weighting system. For this specific point, discussion and exchange between the groups will take place.
Each Working group will have a group leader who will define, in collaboration with the participants, the working protocol (informal working group meetings, exchange of information through electronic mail, etc.). Time will be provided for the Working groups during the Management Committee meetings.
In the course of the second phase, experimental work on pilot sites will start. Experimental results from the vulnerability mapping in various test sites (minimum 1 or 2 per country according to the availability of data and the research under way) will be integrated to define methods of vulnerability mapping. It might be necessary to improve the methods or to find solutions to field problems (identification of the factors, availability of data). During this phase, scientists will also deal with the problem of calibration and evaluation of the vulnerability assessment, taking into account some probabilistic method such as fuzzy logic.
Finally, results of the Action will be gathered and an overlay index method to assess the intrinsic and the specific vulnerability in karstic fissured aquifer (with examples from each country's test sites) will be proposed. It will provide examples and also show the limitations of the method. Recommendations for a harmonization within Europe will be summarized in a booklet. Results and Recommendations will be edited. Editing and presentation of the results in the framework of an international conference will take place during the last 12 months.
Joint meetings with related COST Actions (COST 66/67/682/Coastal karstic aquifers (new action), for instance) will be organized during MCM. Exchanges of information and contact between Working groups of these COST Actions will be promoted.
During the last year of the Action the added value of the cooperation will be evaluated by independent experts.
E.ECONOMIC DIMENSION
On the basis of national estimates provided by the representatives of the interested countries and taking into account the coordination costs to be covered by the COST budget of the European Commission, the overall cost of the activities to be carried out under the Action has been estimated, at 1996 prices, at roughly ECU 8,25 million.
This amount has been evaluated, as far as national staff costs are concerned, on the basis of a participation of an average number of 4 staff per year (1 scientist, 1 PhD student, contribution to diploma project of either graduate students or postgraduate students) for each country. This amount includes also the costs for material and exchange between institutes: ECU 145 000 per year and per country. The coordination costs have been estimated to be ECU 5 000 per country per year.
This amount of ECU 8,25 million is based on the assumption that 11 countries, Belgium, Croatia, France, Greece, Germany, Hungary, Italy, Ireland, Spain, Switzerland and the United Kingdom, participate in the Action. This amount will increase proportionally with new COST partners.
Programme(s)
Topic(s)
Call for proposal
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Switzerland